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Opis ebooka Laboratory handbook - Ivan Scamorza

this book is useful for students that study chemistry and contains several analyses to do on water, drinkable or surface one to better understand what's in it.

Opinie o ebooku Laboratory handbook - Ivan Scamorza

Fragment ebooka Laboratory handbook - Ivan Scamorza

Chemical analysisIntroduction to water studyIvan Scamorza
Laboratory handbook
Part A
Introduction to drinking water study.....................................................................................pg.4
Drinking water analysis.........................................................................................................pg.8
Set of rules.............................................................................................................................pg.36
Part B
Introduction to Surface waters study..................................................................................pg.39
Surface waters analysis.....................................................
Chemical analysisIntroduction to water studyIvan Scamorza
Part a
Introduction to drinking water study…………………………………………………………pg.4
Drinking water analysis………………………………………………………………………pg.8
Chemical analysisIntroduction to water studyIvan Scamorza
Summary
Part one……………………………………………………..……………………………….....pg.4
Set of rules………………………………………………………………………………...pg.4
mineral waters – classification..…………………………………………………………..pg.5
Pathogens and coliform microorganisms…..……………………………………………..pg.7
Bacteriologic analysis methods nods……………………………………………………..pg.7
Part two…………………………………………………………..………………………….…pg.8
Analysis…………………………………………………………………………………...pg.8
Storage and sample taking………………..……………………………………………….pg.8
Sample identifying characters …………………………………………………………….pg.8
Organoleptic analysis…………………………………………………………….………..pg.8
Chemical and physical analyses……….…………………………...........................pg.9
Physical analyses……………………………………………………………………………….....pg.10
pH……………………………………………………………………………..…………....pg.10
Conductivity…………………………………………………………………..……………pg.11
Fix residue…………………………………………………………………….……………pg.12
Chemical analyses…….……………………………………………………………………...pg.13
Organic substances determine…………………………………………………….……..….pg.13
TOC……………………………………………………………………………….………...pg.13
OD – dissolved oxygen……………………………………………………………………..pg.14
Chlorine derivatives…………………………………………………………...……............pg.16
Hardness………………………………………………………………………...…………..pg.16
Total hardness……………………………………………………………………………………….................pg.17
Permanent hardness……………………………………………………………………………………………pg.18
Temporary hardness............................................................................................................................................pg.19
Calcium hardness………………………………………………………………………………….…...............pg.19
Ammonia nitrogen, nitrous, nitric……………………………………………………….......…....pg.20
Ammonia nitrogen…………………………………………………………………………........……pg.20
Nitrous nitrogen…………………………………………………………………………...........…….pg.22
Nitric nitrogen……………………………………………………………………………..…...…….pg.24
Orthophosphates…………………………………………………………………………...................pg.26
Dissolved CO
2
..…………………………………………………………………………………….....pg.28
Chlorides …………………………………………………………………………...…….....…….....pg.29
Sulfates……………………………………………………………..………………...…………........pg.32
Metallic cations………………………………………………….…………………...……………....pg.32
Bacteria charge (total coliforms) ………………………………..…………………...……………....pg.33
Notes (total organic carbon) TOC……………………………........…………………………………pg.34
D.Lgs 2 February 2001, n°.31………………………………………………………………….…....pg.36
3
Chemical analysisIntroduction to water studyIvan Scamorza
Part one
Set of rules
D.lgs 31/01, effective since 31 December 2003, tracks the quality requisites that the human
consumption waters must have, wherever they comes, whether they has taken at the source or
distributes by public aqueducts.
Water can be called (D.Lgs 31/01 art.4) “drinking when it is clear, clean and it doesn’t contain such
quantities or concentration of microorganisms and parasites or other substances dangerous to
human health”.
Water must have different requisites to be defined drinkable and these one are evaluated through
sampling and laboratory analyses that follow the D.Lgs 2.02.2001, n°.31 indications in which are
defined chemical, physical and microbiological maximum acceptable concentrations and guide
values.
Waters must have these values when we use it at home and when is bottled or put in the right
containers, while the water used by the food businesses are controlled during the food or
beverages preparing.
SIAN (Food and Nutrition Hygiene Service) has the role to express the drinking judgment whether
for the human consumption water and the domestic use one.
SIAN does periodic controls to verify that requisites:
1.At the source
2.Adduction installations
3.Distribution network
Any standards dissimilarity leads to precautionary and emergency measures to ensure the water
restoration and the hydra supplying to population, respecting nature and public health.
Mineral waters – classification
Marotta and Sica have done the Italian classification of mineral waters by their use.
Bath waters
Bath waters are classified by the source temperature and the saline composition.
Relative to the saline composition we can classify waters into sulfurous , if there is an high
concentration of sulfur anion; salse waters, if there is an high concentration of chlorine anion;
sulfate waters , if the sulfate anion prevails; bicarbonate waters, if bicarbonate ion prevails.
Waters are also classified by the temperature; cold waters if T<20°C (salse, sulfurous,
bicarbonate); hypothermal 20<T<30°C (salse, sulfurous, bicarbonate); thermal 30<T<40°C (salse,
sulfurous, bicarbonate); hyper thermal T>40°C (salse, sulfurous, bicarbonate).
Chemical analysisIntroduction to water studyIvan Scamorza
Mineral waters
Mineral waters have a fix residue at 180°C lower than 0,2 g/L (olio minerals) or higher than 1g/L
(minerals), instead with an intermediate fix residue we have medium mineral waters.
A specific classification is reported in TAB1.
Periodic controls are forecasted for mineral waters about;
1.study and analysis of the water source land;
2.physical and organoleptic water characters exam;
3.bacteriological exam;
4.quali-quantitative chemical analysis of parameters established by the set of rules.
The mineral water source land study is necessary to decide the distance from houses, industrial
installation and waste deposits that could cause infiltrations and pollution.
Chemical and physical analysis must stay into set of rules parameters and must be stable by time.
Land analysis is furthermore useful to determine quality and quantity of dissolved salts that must
be partially in solution with the water that comes from the land.
Source temperature must be between 9 and 12°C, with weak variations due to seasons change.
Chemical analysisIntroduction to water studyIvan Scamorza
TAB1
1. Oligo-mineral waters [fix residue at 180°C lower than
0,200°/
°°
]
2. medium-mineral waters
A) salse
[fix residue at 180°C higher than
0,200°/
°°
and lower than 1,000 °/
°°
]
1.salse
2. salse-sulfate-alkaline
3. salse-sulphate-alkaline-earth
4. salse-bromine-iodine
5. salse-iodine-sulfate-alkaline
6. salse-iodine-alkaline-earth
3. mineral waters
B) sulfurous
[fix residue at 180°C higher than
1.000 °/
°°
]
1. Sulfurous
2. sulfurous-sulfate-alkaline
3. sulfurous-salse
4. sulfurous-salse-bromine-iodine
5. sulfurous-salse-sulfate-alkaline
6. sulfurous-sulfate-alkaline
C)ferruginous
arsenic
1. Arsenical
2. ferruginous arsenic
D) bicarbonate 1. Bicarbonate-alcaline
2. bicarbonate-alcaline-bromine-
jodine
3. bicarbonate-alcaline-earth
4. bicarbonate-sulphate-alcaline
5. bicarbonate-sulphate-alcaline-earth
E) sulphate 1. Sulphate-alcaline
2. sulphate-alcaline-earth
6
Chemical analysisIntroduction to water studyIvan Scamorza
Pathogen and coli form microorganisms
Pathogen microorganisms enter into water bodies thanks to human and animal dejections.
In that dejection there are a lot of non pathogen species that live a lot in waterways:
bacteriological analysis research non pathogen microorganisms as Escherichia Coli, that normally
lives in the human and animal’s large intestine; billions of these microorganisms leave the human
body like other coli forms as Enterobacter aero genes (it is also in the human faeces).
Coli form presence means the faecal pollution and so that kind of water is not drinkable.
In addition to coli forms are searched:
1. Faecal streptococci: found in hot blood animals’ intestines;
2. Monogenic bacteria: able to process mucilaginous or gummy substances like capsular
structures or extracellular secretions products;
3. Iron bacteria: change iron soluble compounds into insoluble ones (iron hydroxides) that circle
the microorganisms like a case (sphaerotilus) or are secreted to form strips or peduncles.
4. sulphur bacteria: able to live till pH 1 they oxidize sulphur to sulphuric acid and could corrode
tubes (Thiobacillus) or reduce sulphate’s sulphur to H
2
S (desulfovibrio desulfuricans).
Coliform bacteria
BacteriologicalanalysismethodsNods
Bacteriological analysis often determines if water is drinkable or not.
Routine analysis doesn’t provide pathogen bacteria research because detachable only in high
amount and because they don’t live a lot and so they couldn’t be seen.
Bacteriological analysis methods are standard.
They are dictated from WHO (World Health Organization) and they have to be respected diligently
to have an official meaning.
The sample must be indicative of the providing source it comes from and has to be taken in sterile
bottles.
Sample must be analyzed as soon as possible or stored at 0<T<10 °C.
Before the analysis, both all instruments and materials have to be sterilized in silos to kill the
microorganisms living on them.
To reach the aim it can be used flaming (the quickly passage of the sample on the flame).
7
Chemical analysisIntroduction to water studyIvan Scamorza
Part two
Analysis
Dispositions concerning drinking water, dictated by the D.Lgs 2.02.2001, took place 25 December
2003 in Italy.
In this set of rules are written chemical, physical and microbiological guide values and maximum
concentrations permitted, for example is forecasted a minimum annual frequency to analyze the
distribution water network (D.Lgs 2.02.2001, n°.31).
“routine control aims to provide organoleptic and microbiological information of human
consumption water moreover the efficiency of any treatment done on drinking water at regular
intervals, to verify if the values match the parameters dictated by the set of rules” (D.Lgs
2.02.2001 n°.31).
Sample taking and stocking
Glasses colorless emery plug bottles firstly washed with hydrochloric acid and then washed again,
at least three times, with the sample water make sample analytic taking.
The sample water amount depends on the analysis.
If the sample will be taken from a well or a cistern is primary to pay attention not to take the
superficial water or the one at the bottom; instruments help to take the water at the desired
depth are used.
If a faucet or a pump makes the sampling, is better to let the water flown for about 10 minutes to
remove the portion that has been for a longer time in the tubes.
The sample, taken using glass or polyethylene bottles, has to be stored at a lower temperature
than 4°C.
Measurements and doses must be made as faster as possible since the sample arrives in the
laboratory.
IDENTIFYNG CHARACTERS OF THE SAMPLE
Identifying characters of the sample comprehend the brand, the location, the date of the sampling
or buying, and the results of the organoleptic analysis.
ORGANOLEPTIC ANALYSIS
A sample organoleptic analysis expresses an evaluation comprehending sight, sense of smell and
taste.
Set of rules forecasts that taste, sense of smell and color are “acceptable for users” if there aren't
freak variation by time.
COLOR – the color of the sample is compared with distilled water.
Expression of results: colorless or colored respect to distilled water (visible spectra).
TRASPARENCY – water is transparent if clear when is observed across a colorless glass tube with a
diameter of 50 cm.
Expression of results: sample water is clear or unclear.
TASTE – expression of results: indicate if the taste is pleasant or unpleasant at 15-20°C.
8
Chemical analysisIntroduction to water studyIvan Scamorza
SENSE OF SMELL – expression of results: indicate if the water is odorless or have odor until 60°C.
PHYSICAL AND CHEMICAL ANALYSES
European D.Lgs 2.02.2001 n°.31 prescribes the adoption of reference analytic methods to use for
chemical and physical parameters dosages, dictated by the health higher institute of every state,
Such they are capable to measure at least equal concentration to parameter value with a precision